Steam generating plant



May 26, 1931. K

STEAM GENERATING PLANT Filed Sept. 1, 1927 3 Sheets-Sheet l May 26, 1 931. I K 1,807,538

STEAM GENERATING PLANT Filed Sept. 1, 1927 a Sheets-Sheet 2 I $3 I J L L I LC) w T I I. ,7 CL

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May 26, 1931. A, E. LEEK 1,807,538

STEAM GENERATING PLANT 'Fil ed Sept. 1, 1927 3 Sheets-Sheet .3

Patented May 26, 1931 UNITED STATES PATENT OFFICE ALBERT EDWARD LEEK, OF WIG-AN, ENGLAND STEAM GENERATING PLANT Application filed September 1, 1927, Serial No. 216,940, and in Great Britain September 2, 1926.

The'present invention relates to improve ments in steam generating plant and more particularly to superheater arrangements therefor. I

6 According tothe present invention a steam tube or group of tubes is arranged within or without andaxially along and parallel to a flue-gas conduit or tube and thenback axially alongand parallel to a neighbouring flue gas conduitor-tube. Several such arrangements may be connected in series orin parallel or in series-parallel grouping.

In a preferred arrangement the flue gases Whilst contacting with such steam tube or,

tubesalso simultaneously contact with conduit or tube surfaces over which air for furnace combustionor other purposes is passed, and may then subsequently serve for the preheating of such air. and or alternatively the simultaneous heating of boiler feed water or Water for like industrial purposes.

The invention is more particularly described with reference to the accompanying drawings, in which Figure 1 is a sectional elevation through one form of device-for imparting the heat of flue gases to air and to superheater tubes simultaneously.

Flgure 21s a similar View of an arrangement for heating superheater tubes, air, and

water.

Figure 3is a part sectional arrangement of a'modified form of construction.

f'Flue gas at high temperature is passed to 735 the inlet 1 of a casing 2 having end plates 3, l'spaced from its ends 5, 6 respectively; Refractory linings maybe placed at parts such as 7, 8 by way of example to protect metallic surfaces. The flue gas passes from the inlet end of the casing to the opposite end by header units 12. This construction allows of the easy withdrawal and replacement of such superheater tube units, afterrdisconnection at the headers '12 and temporary removal of the casing end 13 and baffle 14.

Air enters the casing at inlet '15 and may pass directly across it to outlet 16 over the outer surfaces of the tubes 9, or may have the length of its passage through said casing increased by the disposition of suitable baffles 14 14 It will consequently be seen that heat from the flue gases is taken up by the steam in the superheater tubes 11 and simultaneously by air passing over the outer surfaces of the flue gas tubes 9. v

In the arrangement shown by way of example the flue gases are led through the casing in multiple pass, leaving at the outlet 17, curved baffles 14, 19, 20 being provided to smoothlyguide the gases at places Where they are required to change the direction offiow, and to avoid dead spaces.

It will further be noticed in this particular arrangement taken by way of example, that the flue gas tubes 9 of the second and third pass contain no superheater tubes, these passes serving'as air heating means alone.

As in certain cases it may be desirable to place the superheater or steam tubes 11 out of the gas circuit, an alternative inlet 21 is provided normally shielded by baflle 22 in the full line position when superheater tubes 11 are in action with gas from inlet 1.

The arrangement illustrated is a referred one in which the air passes through the easing in contraflow to the flue gas.

In the modified construction of Figure 2 taken by way of example of a further application of the present invention, the flue gas tubes 9 of the second and third pass contain water tubes 23 such as boiler feed water tubes, these tubes being connected in series to one another, or in series-parallel groups, and connected to water inlet 24 and outlet 0 25 so that water flow is incontrafiow to the flue gas flow.

The flue gas tubes, as also therefore the water tubes are preferably arranged staggered or in echelon, that is to say the centres. m

of three adjacent tubes lie at the apices of an equilateral triangle.

In certain cases it may be desirable as shown in Figure 3 to set back the end plate 26 at the end of the first or superheater pass allowing greater freedom to the bent ends of the superheater tubes and a freer gas flow When the hinged first pass baffle 22 lies in the dotted line position.

It will be preferred that the air flow, and also if desired the flue gas flow be accelerated by force or induced draught fans or the like.

Further additional smaller bore flue-gas tubes (not shown) may be provided in any spaces adjacent the Walls of the casing, or its false Walls or filling pieces, including the first pass in construction as hereinbefore described.

In a modified form of construction air to be preheated may be passed through a tube such as 11, Figure 3, instead of steam to be super-heated, whilst feed water to be heated can pass through tubes 23 as in that construc tion, or again whilst using the tubes 11 for super-heat purposes the tubes 23 may be used for the pie-heating of air.

I declare that What I claim is 1. A heat interchanger comprising a plurality of flue gas conduits, a plurality of superheater steam tubes each steam tube pass ing axially within and parallel to one conduit of a pair and then back axially Within and parallel to the other conduit of a pair, means to pass said flue gases axially along boiler feed Water tubes after passage along said steam tubes, and means to pass air simultaneously over the opposite side of said flue gas conduits to that adjacent said steam tubes and Water tubes in contraflow to the motion of the flue gas.

2. A heat interchanger comprising a plurality of flue gas conduits, a plurality of superheater steam tubes each steam tube passing axially Within and parallel to one conduit of a pair and then back axially Within and parallel to the other conduit of a pair, a plurality of feed water tubes each Water tube passing axially Within and parallel to one conduit of a pair and then back axially Within and parallel to the other conduit of a pair, means to pass said flue gas first along the conduits containing said steam tubes and then along the conduits containing said Water tubes, and means to pass air simultaneously over the opposite side of said flue gas conduits to that adjacent said steam tubes and water tubes in contraflow to the motion of said flue gas.

3. A heat interchanger comprising in combination a casing. end plates spaced from the ends of said casing, flue tubes uniting said end plates, steam tubes in certain of said flue tubes, Water tubes in certain other of said flue tubes, flue gas inlet and outlet openings external of said end plates, air inlet and outlet openings internal of said end plates and baflle means internal of said end plates to guide air in multiple pass through said casing.

4. A heat interchanger comprising in combination a casing, end plates spaced from the ends of said casing, flue tubes uniting said end plates, steam tubes coaxial Within certain of said flue tubes, Water tubes coaxial Within certain other of said flue tubes, flue gas inlet and outlet openings external of said end plates, air inlet and outlet openings internal of said end plates and baifle means internal of said end plates to guide air in multiple pass through said casin 5. A heat interchanger comprising in combination a casing, end plates spaced from the ends of said casing, flue tubes uniting said end plates, steam tubes in certain of said flue tubes, Water tubes in certain other of said flue tubes, flue gas inlet and outlet openings external of said end plates, air inlet and outlet openings internal of said end plates, baflle means external of said end plates to guide the flue gases in smooth flow and in multiple pass through said casing and baflle means internal of said end plates to guide air in multiple pass through said casing.

6. A heat interchanger comprising in combination a casing, end plates spaced from the ends of said casing, flue tubes uniting said end plates, steam tubes in certain of said flue tubes, Water tubes in certain other of said flue tubes, flue gas inlet and outlet openings external of said end plates, air inlet and out let openings internal of said end plates, baffle means external of said end plates to guide the flue gases in smooth flow and in multiple pass through said casing, and baflie means internal of said end plates to guide air in multiple pass through said casing and in contraflow to the motion of the flue gas.

7. A heat interchanger comprising in combination a casing, end plates spaced from the ends of said casing, flue tubes uniting said end plates, steam tubes in certain of said flue tubes, flue gas inlet and outlet openings external of said end plates, air inlet and outlet openings internal of said end plates, baflie means external of said end plates to guide the flue gases in smooth flow and in multiple pass through said casing, and baflle means internal of said end plates to guide air in multiple pass through said casing in contraflow to the motion of the flue gas.

8. A heat interchanger comprising in combination a casing, end plates spaced from the ends of said casing, flue tubes uniting said end plates, bafiie means external of said end plates to divide said flue tubes into multiple pass arrangement, steam tubes in certain of said flue tubes of the first pass, Water tubes in certain of said flue tubes of succeeding passes, flue gas inlet and outlet openings external of said end plates, air inlet and outlet openings internal of said end plates, selective means to pass flue gas to the flue tubes of the first or second pass, baflie means external of said end plates adapted to move into or out of a position shielding said flue tubes of the first pass from flue gas, and balfle means internal of said end plates to guide air in multiple pass through said interchanger and in contraflow to the motion of the flue gas.

9. A heat interchanger comprising a plurality of flue gas conduits, a plurality of superheater steam tubes, each steam tube passing axially Within and parallel to one conduit of a pair and then back axially within and parallel to the other conduit of a pair, a plurality of boiler feed water tubes located each axially Within and parallel to a flue gas conduit, means cooperating with said flue gas conduits to pass the flue gases along the conduits containing the superheater steam tubes and thereafter along the conduits containing the feed Water tubes, and means to pass air simultaneously over the opposite side of said flue gas conduits to that adjacent said steam tubes and water tubes.

10. A heat interchanger comprising in combination a casing, end plates spaced from the ends of said casing, flue tubes uniting said end plates, steam tubes in certain of said flue tubes of the first pass, Water tubes in certain of said flue tubes of succeeding passes, flue gas inlet and outlet openings external of said end plates, air inlet and outlet openings internal of said end plates, selective means to pass flue gas to the flue tubes of the first or second pass, bafiie means external of said end plates to divide said flue tubes in a multiple pass arrangement and including a baflle adapted to move into or out of a position shielding said flue tubes of the first pass from flue gas.

In Witness whereof, I have hereunto signed my name this 17th day of August, 1927.

ALBERT EDWARD LEEK. 

